The vanadium redox flow battery

Posted by on Aug 7, 2014 in Facilities Management, Industry Trends, Innovation, Site Improvement | 0 comments

If you’re like me, you’ve had to deal with a few batteries in your career. It’s usually one of the weak links in mission-critical environments; and consequently, we find ourselves obsessing over battery condition, life expectancy, and failure rates quite often. We can literally spend millions of dollars each year due to failed cells or end-of-life replacements. Wouldn’t it be nice not to have to deal with that – or even to worry about it?

I have recently (with some excitement, I might add) been investigating vanadium redox flow batteries. These systems use fluids — or more precisely, electrolytes — to store energy. I’m not going to get technical in this post; but if you want to know more today, here’s a Wikipedia link.

How the battery works

Basically, there are two tanks of electrolyte with a membrane in a frame between the two.  The two electrolytes set up a potential across the membrane that allows for the flow of electrons.

The system requires two pumps to circulate the electrolytes into the membrane area. So if you think about it, the only limit to the battery storage capacity is the size of the tanks. From a mission-critical perspective, you can put in redundant pumps (DC-powered, of course, from the battery itself). The battery can be left completely discharged over long periods with no ill effect.  One of the great attributes of the battery is that it can be charged and discharged to and from any state almost infinitely – so there is no more float voltage or conditioning. Life expectancy is 20 or so years based upon fouling of the membrane, life of the tanks and other physical components.

In a data center application, the battery could replace the UPS; and if you think about it, if you have the room, it could even replace the generator. Transfer times from charge to discharge are in the sub-milliseconds, making it ideal to use without complex static transfer switches. In places where the system takes a lot of hits per month (I’m thinking India here), these batteries would be ideal. There would be no need to do quarterly or semi-annual maintenance anymore — just an annual checkup. From this standpoint, these batteries sound ideal, but there are other things to consider.

Is there a downside?

Now for the other side: These batteries are expensive; they require a lot of room for the same power capacity; and the electrolyte is hazardous. Another point is the fact that they are new technology and so education and training will be necessary if they are to gain acceptance in the industry. For example, permitting agencies may be reluctant to approve them and may require very stringent processes and/or structures to address perceived issues.

I believe that these batteries are the future because there are so many upsides to the technology. Even just the reduction of failure points makes it worth being an early adopter.

An interesting aside, these batteries are being considered for use in vehicles. Imagine having an electric car and, instead of filling the tank up with gas, they just drain the discharged electrolyte and put in charged electrolyte. Instead of waiting to charge your battery, the drain and refill would take only a few minutes, and then you can be on your way again. Scientists around the world are working on this technology to increase the power density of the process. Remarkable progress is being made. Imagine doubling or tripling your battery’s capacity just by draining and refilling with new, improved electrolyte.

My feeling is that this new, disruptive technology will change our industry … for the better. Where do you see this technology being used?

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